1. Field of the Invention
The present invention relates to a wheel set structure, and in particular to a hollow wheel set structure without the conventional wheel axis, so as to reduce its weight.
2. The Prior Arts
Presently on the market, a kind of wheel set is available for being installed at the bottom of the main body in the following approach to carry weight: a wheel rack 10 having a connection seat 14 and a pair of fixing arms 12 are provided, to match with a wheel 18 with its center having a wheel axis 16, and a through hole 20 is disposed through the pair of fixing arms 12, as shown in FIG. 1. The connection of the wheel 18 and the pair of fixing arms 12 is achieved through using a fixing piece 22 to run through the through hole 20 and wheel 18, and then it is locked and fixed with a positioning piece 24.
However, in such a design structure, the use of a pair of fixing arms 12 will make the production cost of the wheel rack 10 rather high. Moreover, the approach of using the fixing piece 22 having locking threads to lock and fix with the positioning piece 24 could increase the number of elements utilized, and make the overall structure much more complicated. In addition, the disposition of a wheel 18 having a wheel axis 16 could increase the weight of the wheel set.
Therefore, presently, the design and performance of the wheel set of the prior art is not quite satisfactory, and it has much room for improvements.